Just a suggestion, but you should offer alternative mounting brackets for them that allow you to mount them without having to use the spacers on the M1 manifolds. makes for a cleaner look.
Just for reference, here is what mine look like with my custom made mounts for the 4bbl M1 I just put on without using the spacers from the install kit. Took me about 5 minutes to make each of the short brackets due to my fuel rail design and checking to make sure the bends and length were correct. And I didn't have any specialized tools. just a bench vise, a hammer, hacksaw and drill bits.
And here's how they looked on my old 2bbl.